1. Field of the Invention
The present invention relates generally to a pre-crash side airbag device which deploys a main airbag and an auxiliary airbag before collision happens when high-speed side collision is expected, so that a vehicle occupant is pushed in the direction opposite to the collision, thereby more actively protecting the vehicle occupant, that is, the present invention works in a more improved manner than the existing manner in which a main airbag is deployed to protect vehicle occupants in the event of a side collision.
2. Description of the Related Art
With the recently high interest in the safety of vehicle occupants together with the functions and convenience of vehicles, the importance of safety devices capable of safely protecting vehicle occupants to the utmost in the event of vehicle accidents has been gradually magnified.
From among various safety devices, particularly airbags function to prevent vehicle occupants from being injured in conjunction with seat belts in the event of a front or side vehicle collision.
Generally, airbags are classified into front airbags for protecting vehicle occupants in the event of a front vehicle collision and side airbags for protecting vehicle occupants in the event of side vehicle collision.
Such a side airbag is well known for usually including a side collision detection sensor, an airbag control unit, and a side airbag module. When side collision energy is input from another vehicle or an object, the side collision detection sensor detects the collision energy and sends the measurement value thereof to the airbag control unit.
The airbag control unit compares the measurement value received from the side collision detection sensor with a reference value, and determines whether to allow the deployment of the side airbag module. When an airbag cushion is deployed by the side airbag module, the head and ribs of a vehicle occupant are protected from the side collision energy.
Korean Patent Registration No. 512427 discloses a technology related to the side airbag of a vehicle. Here, auxiliary chambers are additionally provided in the respective sides of the chest chamber unit and head chamber unit of a main chamber, some of the gas filling the main chamber flows into the auxiliary chambers and the auxiliary chambers are inflated, so that the width of a side airbag can expand in both directions toward a vehicle occupant and the side of a vehicle body, with the result that the side airbag is inflated in both directions toward the vehicle occupant and the side of the vehicle body within a short time even though there is only a narrow gap between the vehicle occupant and the side of the vehicle body, thereby effectively minimizing the injury of a vehicle occupant by sufficiently protecting the vehicle occupant and especially by protecting the chest and head of the vehicle occupant.
However, with regard to a side airbag disclosed in Korean Patent Registration No. 512427, a side airbag is divided into a main chamber and an auxiliary chamber for the purpose of reducing the severity of injuries of a vehicle occupant, and has a mechanism for operating an airbag when vehicle collision actually occurs. Therefore, when a high-speed side collision occurs, the entry speed of collision energy is faster than the deployment speed of an airbag, so that the side airbag cannot be normally deployed, thereby creating a problem in that a vehicle occupant cannot be perfectly protected.
That is, in the event of a high-speed side collision in which the collision energy is considerable large, the side of a vehicle body is deformed and encroaches on the place where a vehicle occupant is seated, so that a collision between the side of the vehicle body and the vehicle occupant occurs. Therefore, there are problems in that a side airbag cannot be properly deployed due to the deformation of the side of a vehicle body, and in that, even though a side airbag is deployed, the interval between a vehicle occupant and the side of a vehicle body is narrow, so that a vehicle occupant cannot be sufficiently protected.